[Medellin, Colombia. Images via Getty]

A Grey-bellied Night Monkey (Aotus Lemurinus) born in captivity one month ago, climbs onto his mother on May 19, 2009 at the Santa Fe Zoo, in Medellin, Antioquia Department, Colombia. The Night Monkey is an endangered species. AFP PHOTO/Raul Arboleda (Photo credit should read RAUL ARBOLEDA/AFP/Getty Images)